//  Copyright (c) 2018-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under both the GPLv2 (found in the
//  COPYING file in the root directory) and Apache 2.0 License
//  (found in the LICENSE.Apache file in the root directory).
#pragma once

#include "monitoring/instrumented_mutex.h"
#include "options/db_options.h"
#include "rocksdb/listener.h"
#include "rocksdb/status.h"
#include "rocksdb/terark_namespace.h"

namespace TERARKDB_NAMESPACE {

class DBImpl;

class ErrorHandler {
 public:
  ErrorHandler(DBImpl* db, const ImmutableDBOptions& db_options,
               InstrumentedMutex* db_mutex)
      : db_(db),
        db_options_(db_options),
        bg_error_(Status::OK()),
        recovery_error_(Status::OK()),
        db_mutex_(db_mutex),
        auto_recovery_(false),
        recovery_in_prog_(false) {}
  ~ErrorHandler() {}

  void EnableAutoRecovery() { auto_recovery_ = true; }

  Status::Severity GetErrorSeverity(BackgroundErrorReason reason,
                                    Status::Code code, Status::SubCode subcode);

  Status SetBGError(const Status& bg_err, BackgroundErrorReason reason);

  Status GetBGError() { return bg_error_; }

  Status GetRecoveryError() { return recovery_error_; }

  Status ClearBGError();

  bool IsDBStopped() {
    return !bg_error_.ok() &&
           bg_error_.severity() >= Status::Severity::kHardError;
  }

  bool IsBGWorkStopped() {
    return !bg_error_.ok() &&
           (bg_error_.severity() >= Status::Severity::kHardError ||
            !auto_recovery_);
  }

  bool IsRecoveryInProgress() { return recovery_in_prog_; }

  Status RecoverFromBGError(bool is_manual = false);
  void CancelErrorRecovery();

 private:
  DBImpl* db_;
  const ImmutableDBOptions& db_options_;
  Status bg_error_;
  // A separate Status variable used to record any errors during the
  // recovery process from hard errors
  Status recovery_error_;
  InstrumentedMutex* db_mutex_;
  // A flag indicating whether automatic recovery from errors is enabled
  bool auto_recovery_;
  bool recovery_in_prog_;

  Status OverrideNoSpaceError(Status bg_error, bool* auto_recovery);
  void RecoverFromNoSpace();
};

}  // namespace TERARKDB_NAMESPACE
